Proximity switch

Abstract

Proximity switch with a coil arrangement having at least one coil and an evaluation circuit arranged downstream of said coil arrangement for obtaining a switching signal when a trip feature of the coil arrangement approaches a desired response distance, wherein the at least one coil is formed by coil sections ( 8 ) connected electrically in series, preferably disposed next to one another, axially in parallel, with a same winding direction.

1. Proximity switch with a coil arrangement having at least one coil and an evaluation circuit arranged downstream of said coil arrangement for obtaining a switching signal when a trip feature of the coil arrangement approaches a desired response distance, wherein the at least one coil is formed by coil sections ( 8 ) connected electrically in series, preferably disposed next to one another, axially in parallel, with a same winding direction, wherein said proximity switch has a ratio of sensor area diameter to operating distance of at least 4:3 for operating distances in excess of 30 mm. 
   
   
     2. Proximity switch according to  claim 1 , wherein the coil sections ( 8 ) are planar coils disposed on a plate ( 7 ). 
   
   
     3. Proximity switch according to  claim 1 , wherein the coil sections ( 8 ) form at least one of two differential coils ( 2 ,  3 ) of a proximity switch having a transmitting coil ( 4 ) and the two differential coils ( 2 ,  3 ). 
   
   
     4. Proximity switch according to  claim 3 , wherein the transmitting coil ( 4 ) is located between the two differential coils ( 2 ,  3 ) and is shielded by an attenuating ring ( 13 ). 
   
   
     5. Proximity switch according to  claim 1 , wherein the coil formed by the coil sections ( 8 ) is not shielded. 
   
   
     6. Proximity switch according to  claim 1 , wherein the coil sections ( 8 ), of which there are in particular four in number, are disposed symmetrically in a plane. 
   
   
     7. Proximity switch according to  claim 1 , wherein a diameter of the coil sections is considerably less than a diameter of an active surface ( 10 ) behind which they are disposed. 
   
   
     8. Proximity switch according to  claim 7 , wherein the coil formed by coil sections ( 8 ) is located closest to the active surface. 
   
   
     9. Proximity switch according to  claim 1 , wherein the coil formed by the coil sections ( 8 ) is an oscillating circuit coil of an inductive proximity switch. 
   
   
     10. Proximity switch according to  claim 1 , wherein the coil sections ( 8 ) each have an associated ferrite coil former ( 11 ). 
   
   
     11. Proximity switch as recited in  claim 1 , wherein said proximity switch is operable in the direct vicinity of metal masses. 
   
   
     12. Proximity switch as recited in  claim 1 , wherein said switch is flush mountable on a metal mass and has an operating distance of at least 30 mm. 
   
   
     13. Proximity switch as recited in  claim 12 , wherein said operating distance may be selectively increased by dividing said at least one coil into a plurality of coil sections. 
   
   
     14. Proximity switch with a coil arrangement having at least one coil and an evaluation circuit arranged downstream of said coil arrangement for obtaining a switching signal when a trip feature of the coil arrangement approaches a desired response distance, wherein the at least one coil is formed by coil sections ( 8 ) connected electrically in series, preferably disposed next to one another, axially in parallel, with a same winding direction,
 wherein said proximity switch is flush mountable and has a sensor area diameter of at least 40 mm and operating distances of at least 30 mm.  
 
   
   
     15. Proximity switch with a coil arrangement having at least one coil and an evaluation circuit arranged downstream of said coil arrangement for obtaining a switching signal when a trip feature of the coil arrangement approaches a desired response distance, wherein the at least one coil is formed by coil sections connected electrically in series, and axially in parallel, with a same winding direction,
 wherein said proximity switch has a sensor area diameter of at least 40 mm.  
 
   
   
     16. Proximity switch with a coil arrangement having at least one coil and an evaluation circuit connected to said coil arrangement for obtaining a switching signal when a trip feature of the coil arrangement approaches a desired response distance, wherein the at least one coil is formed by coil sections connected electrically in series, and axially in parallel, wherein said proximity switch has a ratio of sensor area diameter to operating distance of at least 4:3 for operating distances in excess of 30 mm. 
   
   
     17. Proximity switch as recited in  claim 16 , wherein said proximity switch is flush mountable.